First of all, let us establish that jesus had preexistence.
John 6:38
[38]For I came down from heaven, not to do mine own will, but the will of him that sent me.
For jesus to have said, he came from heaven implies preexistence.
Comparatively speaking, saying i came down from Baguio it logically manifests that the one talking here was talking likewise in Baguio as he is the same man talking here.
In like manner, saying i came down from heaven manifests that he was a thinking talking being in heaven as he was the same person talking on earth.
That spells, preexistence. It was not speaking about his human component but otherwise bec man in nature came from the womb.
Job 31:15
[15]Did not he that made me in the womb make him? and did not one fashion us in the womb?
He being the god component of jesus existed as a thinking being prior to incarnation. That supports the idea that he was with god in the beginning as the word–a preexisting status.
John 1:1-2
[1]In the beginning was the Word, and the Word was with God, and the Word was God.
[2]The same was in the beginning with God.
More so, he was the wisdom of god. And being that, he existed before creation.
1 Corinthians 1:24
[24]But unto them which are called, both Jews and Greeks, Christ the power of God, and the wisdom of God.
The wisdom existed before creation.
Proverbs 8:12,22-31
[Ì wisdom dwell with prudence, and find out knowledge of witty inventions.
[22]The LORD possessed me in the beginning of his way, before his works of old.
[23]I was set up from everlasting, from the beginning, or ever the earth was.
[24]When there were no depths, I was brought forth; when there were no fountains abounding with water.
[25]Before the mountains were settled, before the hills was I brought forth:
[26]While as yet he had not made the earth, nor the fields, nor the highest part of the dust of the world.
[27]When he prepared the heavens, I was there: when he set a compass upon the face of the depth:
[28]When he established the clouds above: when he strengthened the fountains of the deep:
[29]When he gave to the sea his decree, that the waters should not pass his commandment: when he appointed the foundations of the earth:
[30]Then I was by him, as one brought up with him: and I was daily his delight, rejoicing always before him;
[31]Rejoicing in the habitable part of his earth; and my delights were with the sons of men.
That preexisting word or logos in greek has the nature of god. Nature in the sense that he has the shape of god before incarnation.
Philippians 2:6-7
[6]Who, being in the morphe (shape or nature) of God, thought it not robbery to be equal with God:
[7]But made himself of no reputation, and took upon him the form of a servant, and was made in the likeness of men:
That as having exact copy of bodily nature with god almighty.
Hebrews 1:3
[3]Who being the brightness of his glory, and the character (exact copy) of his person, and upholding all things by the word of his power, when he had by himself purged our sins, sat down on the right hand of the Majesty on high;
Now that i have presented you with jesus’ preexistence, let us see how he is truly god.
JOHN 1:1-2,14,18
The word was god…in the beginning with god…the word become flesh…the only begotten god
Note how jesus being the word was god and was in the beginning with god, it conforms how he was the begotten god. Both in aspect of deity. It corroborates how the word was the begotten god, much so, that preexistence supports this idea.
The only begotten god is “monogenes theos” and is present in the early manuscripts like p66, p75, codex sinaiticus, syriac peshitta etc…
So to say that jesus is mere man is erroneous. He was both god and man.
I presented you with proofs that jesus prior to incarnation was a preexisting god. That is the first of his dual nature. This preexisting god came down to earth and he was prepared a human body.
Hebrews 10:5
[5]Wherefore when he cometh into the world, he saith, Sacrifice and offering thou wouldest not, but a body hast thou prepared me:
What will he do to the prepared body after coming from heaven?
Logically, he would indwell in it.
1 John 4:2
[2]Hereby know ye the Spirit of God: Every spirit that confesseth that Jesus Christ is come en (into) the flesh is of God:
This dual nature can be manifested through jesus’ words.
John 8:40
[40]But now ye seek to kill me, a man that hath told you the truth, which I have heard of God: this did not Abraham.
That speaks of the prepared body as the human component of jesus.
John 6:38
[38]For I came down from heaven, not to do mine own will, but the will of him that sent me.John 6:38
That speaks of the preexisting god as his god component. By this we know, jesus was both god and man.